The present application relates to the technical field of bathroom accessories, and in particular to a backflow prevention device and a backflow prevention system connected between drinking water and bathroom facilities.
Bathroom apparatuses (e.g. a toilet) are typically connected to a drinking water system for water supply, which may result in a potential polluting water downstream, and the water in a bathroom apparatus goes against the flow, as a result of back pressure or siphonage, to the upstream drinking water system such that the upstream drinking water is polluted.
At the present, a backflow prevention device would typically be provided to avoid the occurrence of the above phenomenon and to ensure the safety of a drinking water system.
Backflow prevention devices commonly seen on the market usually use a control circuit to control water quantity so as to achieve the goal of backflow prevention. For example, a backflow prevention device connected between a bathroom facility and a drinking water system, as disclosed by Chinese Patent Application No. 201110071501.5, uses a contact pin-type or capacitance-type structure to control the water level of the backflow prevention device. As a result, the device has a complex structure and relatively poor reliability, the circuit part is in a humid environment and tends to be damaged.
The backflow prevention device for a toilet water injection valve disclosed by Chinese Patent Application No. 201080015167.5 requires that a float rotates around the axis so as to drive the plug element thereon to control an open/close hole to open or close. It further requires a special configuration of a backflow prevention part having a backflow prevention sheet, which, first, closely attaches to the groove of an action control part through the backflow prevention sheet's own recovery force, and then, tightly presses the same through back pressure, thereby cutting off the communication between the water supply pipe and the water tank. Such a configuration leads to a complex structure thereof, and requires a relatively powerful recovery force of the backflow prevention sheet. The structural configuration and operations of both the float and the backflow prevention part are relatively complex and not precise, and the running is not steady.